Long-Term Association of an Intensive Lifestyle Intervention on Mortality: The Look AHEAD Study

TL;DR

A long-term study found that intentional weight loss in people with type 2 diabetes and obesity modestly reduced overall mortality risk over 23 years, especially among Hispanic participants.

Contribution

This study extends the 17-year follow-up of the Look AHEAD trial to 23 years, revealing a modest mortality benefit from an intensive lifestyle intervention.

Findings

Intensive lifestyle intervention was associated with a 11% lower all-cause mortality risk compared to diabetes support and education.

The mortality benefit was most pronounced among Hispanic participants.

There were no significant interactions between treatment and age, sex, or cardiovascular disease history.

Abstract

Although weight loss is recommended for individuals with type 2 diabetes and obesity to improve diabetes- and obesity-related risk factors, few studies have examined the effects of intentional weight loss on mortality. Look AHEAD, a randomized trial in 5,145 individuals aged 45-76 yrs with type 2 diabetes and overweight/obesity comparing an intensive lifestyle intervention (ILI) designed to achieve 7% weight loss to diabetes support and education (DSE), previously found no significant differences in all-cause mortality during 10 yrs of intervention or at 17 yrs of follow-up. Since the effects of intentional weight loss on mortality risk may take many years to emerge, we conducted a follow-up examination of all-cause mortality over 23 yrs of follow-up using proportional hazards regression. Interactions between ILI and mortality were also examined in pre-specified subgroups. A total of 800 deaths in ILI and 861 deaths in DSE were observed over 80,725 person-yrs. ILI experienced a lower incidence of all-cause mortality relative to DSE (HR [95% CI]: 0.89 [0.81, 0.98]). There were no significant interactions between treatment and age, sex, or cardiovascular disease history. However, there were significant race/ethnicity by treatment interactions (p = 0.01), with HRs (95% CIs) for participants identifying as African American 0.96 (0.75, 1.23), Caucasian 0.94 (0.84, 1.05), and Hispanic 0.54 (0.39, 0.74). In middle aged and older adults with type 2 diabetes and overweight/obesity, intentional weight loss modestly reduced all-cause mortality risk over 23 yrs of follow-up, which appeared to be largely driven by a reduction in mortality among participants of Hispanic ethnicity.